Opposition Leader Tony Abbott, however, has called the ad "outlandish" and branded it "low politics".

The advertisements, reminiscent of the Grim Reaper AIDS awareness campaign of the 1980s, accuse Mr Abbott of planning to cut public service jobs, tinker with penalty rates and "cut billions from health and education".

"I've always said that the contemporary Labor Party are hopeless at government but brilliant at low politics," Mr Abbott said.

"What we're going to see is a barrage of union-funded negative advertising, I understand it's already started, and that means this election is going to be a struggle."

Mr Abbott said the Prime Minister "should be better than that".

"It is embarrassing that a government which has now been in power for almost six years... is making a whole series of absolutely outlandish and false claims about the Opposition," he said.

"I make no apology whatsoever for the ads that we have on air at present because they are policy based," he said.

Speaking at a Medicare local facility in the northern NSW city of Lismore, Mr Rudd said the ads "put a spotlight on Mr Abbott, who has a strategy of turning himself into a tiny target, not talking to anybody about where his $70 billion worth of cuts to jobs, health and education will fall".

"I'm not about to be silent ... because Mr Abbott's political strategy says he should be mum about it," he said.

"The Australian people in this democracy deserve to have a clear choice and right now they've got a guy wrapping himself up into a tiny ball."

He said Labor was simply "returning fire" after "two weeks of wall to wall negative attacks" from the Coalition.

It has fallen four points since the Newspoll taken at the beginning of the election campaign, and is half that of the heady heights he reached in the months after beating John Howard.

Mr Rudd said the campaign was "still in the second quarter".

I'm a fighter ... I won't take a backwards step and we will fight this through to the conclusion of the campaign

Prime Minister Kevin Rudd

"I'm a fighter ... and I will continue to fight for Australian families, frontline health care workers and the people who depend on an Australian Labor government to stand up for them," he said.

"I won't take a backwards step and we will fight this through to the conclusion of the campaign."

Voter dissatisfaction with Mr Rudd has jumped six points to 54 per cent, while Mr Abbott's dissatisfaction rating fell just one point to 51 per cent.

Abbott insists winning 'like climbing Mount Everest'

Mr Abbott has been able to make up some ground in the opposite direction. His satisfaction rating rose three points to 41 per cent.

Labor's primary support is also at its lowest level since Mr Rudd wrested the Prime Minister's job back, with the Coalition leading the ALP on primary support 47 per cent to 34.

Labor has also fallen further behind the Coalition on a two-party preferred basis, with the Coalition now holding a 54 to 46 per cent lead.

I've always said winning from opposition is like climbing Mount Everest and nothing that has happened over the last few days has changed my judgment

Opposition Leader Tony Abbott

When asked about the Newspoll this morning, Mr Abbott said there was still two weeks to go.

"I've always said winning from opposition is like climbing Mount Everest and nothing that has happened over the last few days has changed my judgment," he said.

"The point I will be making on September 8 should there be a change of government: Australia is under new management and Australia is once more open for business."

The poll has a margin of error of 3 per cent.

Labor pledges stroke care as Coalition sells small business policy

Mr Rudd has campaigned in the Lismore-based seat of Page in northern New South Wales, announcing $50 million to establish a network of stroke care co-ordinators across the country.

"This is a big medical challenge for our great Australian family," he said.

"If you find yourself in difficulty with stroke then these folk are there to work out your co-ordinated care the minute you leave hospital."

Mr Abbott spruiked the Coalition's small business policy while campaigning in the Sydney seat of Bennelong - once held by John Howard and famously won by Labor's Maxine McKew in the 2007 election.

He also announced a Coalition government would crackdown on gun crime by boosting funding for Customs screening and introduce a minimum mandatory sentence of five years' jail for people caught bringing in illegal firearms.